The impact of bacterial diversity on resistance to biocides in oilfields

Extreme conditions and the availability of determinate substrates in oil fields promote the growth of a specific microbiome. Sulfate-reducing bacteria (SRB) and acid-producing bacteria (APB) are usually found in these places and can harm important processes due to increases in corrosion rates, biofouling and reservoir biosouring. Biocides such as glutaraldehyde, dibromo-nitrilopropionamide (DBNPA), tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and alkyl dimethyl benzyl ammonium chloride (ADBAC) are commonly used in oil fields to mitigate uncontrolled microbial growth. The aim of this work was to evaluate the differences among microbiome compositions and their resistance to standard biocides in four different Brazilian produced water samples, two from a Southeast Brazil offshore oil field and two from different Northeast Brazil onshore oil fields. Microbiome evaluations were carried out through 16S rRNA amplicon sequencing. To evaluate the biocidal resistance, the Minimum Inhibitory Concentration (MIC) of the standard biocides were analyzed using enriched consortia of SRB and APB from the produced water samples. The data showed important differences in terms of taxonomy but similar functional characterization, indicating the high diversity of the microbiomes. The APB and SRB consortia demonstrated varying resistance levels against the biocides. These results will help to customize biocidal treatments in oil fields

La coepidemia de dengue y COVID-19 en Brasil : entre los desafíos en su manejo y las consecuencias de la desigualdad socioeconómica

SARS-CoV-2, the etiological agent of COVID-19, spread worldwide, reaching pandemic status in March 2020. In this scenario, dengue epidemics continue to impact endemic countries. Taking into account an increase in dengue cases worldwide, the COVID-19 pandemic may signal a serious danger to global public health. In some countries the pandemic coincided with already installed dengue epidemics. Thus, understanding the collective constituents of arboviruses in pandemic times is fundamental for a significant analysis. The present work brings a narrative review elucidating important impacts resulting from the co-epidemic and its consequences in a broader perspective. Problems with the differential diagnosis of these infections are aggravating factors for the decision of clinical management and prognosis of infected individuals. In addition, socioeconomic characteristics and ethnicity are fundamental factors for both dengue transmission dynamics and COVID-19. It also stands out, a scenario that represents a high risk of collapse for health services in facing challenges for combating and managing resources. Therefore, we conclude that in order to overcome the crisis of simultaneous epidemics and their serious consequences, historical aspects and their relationship with the conditions of social vulnerability need to be taken into account, in addition to promoting specific actions for their combat.O SARS-CoV-2, agente etiológico da COVID-19, se espalhou pelo mundo, atingindo o status de pandemia em março de 2020. Neste cenário, as epidemias de dengue continuam a impactar os países endêmicos. Levando em consideração o aumento dos casos de dengue em todo o mundo, a pandemia de COVID-19 pode sinalizar um sério perigo para a saúde pública global. Em alguns países, a pandemia coincidiu com epidemias de dengue já instaladas. Assim, compreender os constituintes coletivos das arboviroses em tempos de pandemia é fundamental para uma análise significativa. O presente trabalho traz uma revisão narrativa elucidando impactos importantes decorrentes da co-epidemia e suas consequências em uma perspectiva mais ampla. Problemas com o diagnóstico diferencial dessas infecções são fatores agravantes para a decisão do manejo clínico e prognóstico dos indivíduos infectados. Além disso, as características socioeconômicas e etnia são fatores fundamentais tanto para a dinâmica de transmissão da dengue quanto para a COVID-19. Destaca-se também, um cenário que representa alto risco de colapso para os serviços de saúde no enfrentamento dos desafios para o combate e gestão de recursos. Conclui-se, portanto que, para superar a crise das epidemias simultâneas e suas graves consequências, devem ser considerados os aspectos históricos e sua relação com as condições de vulnerabilidade social, além da promoção ações específicas para o seu combate.El SARS-CoV-2, el agente etiológico de COVID-19, se propagó por todo el mundo y alcanzó el estado de pandemia en marzo de 2020. En este escenario, las epidemias de dengue continúan afectando a los países endémicos. Teniendo en cuenta un aumento de los casos de dengue en todo el mundo, la pandemia de COVID-19 puede indicar un grave peligro para la salud pública mundial. En algunos países, la pandemia coincidió con epidemias de dengue ya instaladas. Por lo tanto, comprender los componentes colectivos de los arbovirus en tiempos de pandemia es fundamental para un análisis significativo. El presente trabajo trae una revisión narrativa que aclara los impactos importantes resultantes de la co-epidemia y sus consecuencias en una perspectiva más amplia. Los problemas con el diagnóstico diferencial de estas infecciones son factores agravantes para la decisión de manejo clínico y pronóstico de los individuos infectados. Además, las características socioeconómicas y la etnia son factores fundamentales tanto para la dinámica de transmisión del dengue como para el COVID-19. También se destaca, escenario que representa un alto riesgo de colapso de los servicios de salud ante los desafíos de combate y gestión de recursos. Por tanto, concluimos que para superar la crisis de epidemias simultáneas y sus graves consecuencias, es necesario tener en cuenta los aspectos históricos y su relación con las condiciones de vulnerabilidad social, además de promover acciones específicas para su combate

Microbiota potentialized larvicidal action of imidazolium salts against Aedes aegypti (diptera: culicidae)

Mosquitoes are important vectors of pathogens due to their blood feeding behavior. Aedes aegypti (Diptera: Culicidae) transmits arboviruses, such as dengue, Zika, and Chikungunya. This species carries several bacteria that may be beneficial for its biological and physiological development. Therefore, studying the response of its microbiota to chemical products could result in vector control. Recently, imidazolium salts (IS) were identified as effective Ae. aegypti larvicides. Considering the importance of the mosquito microbiota, this study addressed the influence of IS on the bacteria of Ae. aegypti larvae. After exposition of larvae to different IS concentrations, the cultured microbiota was identified through culturomics and mass spectrometry, and the non-cultivated microbiota was characterized by molecular markers. In addition, the influence of the IS on axenic larvae was studied for comparison. There was an alteration in both cultivable species and in their diversity, including modifications in bacterial communities. The axenic larvae were less susceptible to the IS, which was increased after exposing these larvae to bacteria of laboratory breeding water. This highlights the importance of understanding the role of the larval microbiota of Ae. aegypti in the development of imidazolium salt-based larvicides. Such effect of IS towards microbiota of Ae. aegypti larvae, through their antimicrobial action, increases their larvicidal potential

Study of a new formulation based on ionic liquids for mosquito control

Os mosquitos são conhecidos por transmitir doenças como malária, dengue, Zika, febre amarela e Chikungunya. Uma das formas mais eficazes de combater as populações de mosquitos antes que se reproduzam e transmitam doenças é através da utilização de larvicidas. Muitas pesquisas têm se concentrado no desenvolvimento de novos compostos larvicidas mais eficazes e menos prejudiciais ao meio ambiente e organismos não-alvo. Nesse contexto, esta tese de doutorado investigou os efeitos de sais imidazólicos como uma nova classe de compostos larvicidas para mosquitos. Os resultados indicaram que os sais imidazólicos são altamente eficazes como larvicidas para Culex quinquefasciatus e seguros para organismos não-alvo testados. Além disso, foram examinados os efeitos desses compostos na microbiota bacteriana em de larvas Aedes aegypti e Aedes albopictus de campo, o que pode levar a novas estratégias de controle de mosquitos no futuro. Foi desenvolvido um formulado com base em sais imidazólicos e sua eficácia foi testada em diferentes temperaturas e em ensaios simulados de campo, demonstrando que é eficaz em diferentes condições ambientais. Em resumo, esta pesquisa destaca a importância do desenvolvimento de novos compostos larvicidas para o controle de mosquitos, especialmente aqueles que são vetores de doenças. Os sais imidazólicos são uma classe promissora de compostos larvicidas, com eficácia e segurança demonstradas em testes em larvas de mosquitos e organismos não-alvo. Eles têm o potencial de se tornarem uma importante ferramenta no controle de mosquitos e na prevenção da transmissão de doenças por esses vetores.Mosquitoes are known to transmit diseases such as malaria, dengue, Zika, yellow fever, and Chikungunya. One of the most effective ways to combat mosquito populations before they reproduce and transmit diseases is using larvicides. Many research studies have focused on developing new, more effective, and less harmful larvicidal compounds for the environment and non-target organisms. In this context, this doctoral thesis investigated the effects of imidazole salts as a new class of larvicidal compounds for mosquitoes. The results indicated that imidazole salts are highly effective as larvicides for Culex quinquefasciatus and safe for tested non-target organisms. In addition, the effects of these compounds on the bacterial microbiota of field Aedes aegypti and Aedes albopictus larvae were examined, which may lead to new mosquito control strategies in the future. A formulated product based on imidazole salts was developed and its efficacy was tested at different temperatures and in simulated field assays, demonstrating effectiveness in different environmental conditions. In summary, this research highlights the importance of developing new larvicidal compounds for mosquito control, especially those that are disease vectors. Imidazole salts are a promising class of larvicidal compounds, with efficacy and safety demonstrated in tests on mosquito larvae and non-target organisms. They have the potential to become an important tool in mosquito control and the prevention of disease transmission by these vectors

Action of imidazolium salts on the microbiota of Aedes aegypti (Dptera: Culicidae) larvae

Mosquitos são considerados importantes vetores de agentes patogênicos devido à sua característica hematofágica. Dentre as diversas espécies de importância para a saúde pública, Aedes aegypti se destaca por ser capaz de manter, replicar e transmitir inúmeros microrganismos causadores de doenças como a dengue, febre amarela urbana, zika e chinkungunya. Contudo, algumas relações podem ser benéficas, especialmente com bactérias, cuja interação auxilia no desenvolvimento, nutrição, reprodução e imunidade do mosquito. O controle deste vetor é a principal forma de impedir a disseminação dos patógenos, porém o uso de produtos químicos e biológicos levou ao desenvolvimento de populações resistentes e, consequentemente, a uma maior dificuldade em controlar suas populações. Recentemente, sais imidazólicos mostraram-se extremamente eficazes como larvicidas, mesmo em baixas concentrações. Estes já são utilizados na indústria farmacêutica como antifúngicos, antibacterianos e até no tratamento contra o câncer. Considerando essa atividade bactericida, este estudo propôs testar se sais imidazólicos teriam ação sobre a microbiota de larvas de Ae. aegypti que pudesse induzir a sua morte. Assim, as larvas foram expostas a diferentes concentrações de dois sais imidazólicos sendo, em seguida, identificada a microbiota cultivável através de uma abordagem culturômica e diversidade de bactérias através de técnicas moleculares. Além disso, comparou-se a ação do sal em larvas axênicas. Os resultados mostraram que houve alteração tanto nas espécies cultiváveis, como na diversidade, inclusive modificando as comunidades bacterianas. Além disso, larvas axênicas se tornam menos suscetíveis aos sais imidazólicos. Este é o primeiro trabalho que demonstra sais imidazólicos interagindo com a microbiota de larvas de Ae. aegypti, além de prover um primeiro insight sobre o seu modo de ação.Mosquitoes are considered important vectors of pathogens due to their hematophagy characteristics. Among the several species of importance for public health, Aedes aegypti stands out for being able to maintain, replicate and transmit numerous microorganisms that cause diseases such as dengue fever, urban yellow fever, zika, and chikungunya. However, some relationships may be beneficial, especially with bacteria, whose interaction assists in the development, nutrition, reproduction and immunity of the mosquitoe. Controlling this vector is the main way to prevent pathogens from spreading, but the use of chemical and biological products has led to the development of resistant populations and, consequently, to greater difficulty in cotrolling them. Recently, imidazole salts have proven to be extremely effective as larvicides, even at low concentrations. They are already used in the pharmaceutical industry as anti fungal, anti bacteria and even as cancer treatment. Considering this bactericidal activity, this study proposed to test if imidazolic salts would have action on the microbiota of Ae. aegypti that could induce its death. Thus, the larvae were exposed to different concentrations of two imidazole salts, and then the cultured microbiota was identified through a culturomics approach and bacterial diversity through molecular techniques. In addition, the action of salt on axenic larvae was compared. The results showed that there was alteration both in the cultivable species, as in the diversity, including the modification of bacterial communities. In addition, axenic larvae became less susceptible to imidazole salts. This is the first work that demonstrates imidazole salts interacting with the larval microbiota of Ae. aegypti, as well as it provides the first insight into its mode of action

The great potential of entomopathogenic bacteria Xenorhabdus and Photorhabdus for mosquito control : a review

The control of insects of medical importance, such as Aedes aegypti and Aedes albopictus are still the only effective way to prevent the transmission of diseases, such as dengue, chikungunya and Zika. Their control is performed mainly using chemical products; however, they often have low specificity to non-target organisms, including humans. Also, studies have reported resistance to the most commonly used insecticides, such as the organophosphate and pyrethroids. Biological control is an ecological and sustainable method since it has a slow rate of insect resistance development. Bacterial species of the genera Xenorhabdus and Photorhabdus have been the target of several research groups worldwide, aiming at their use in agricultural, pharmaceutical and industrial products. This review highlights articles referring to the use of Xenorhabdus and Photorhabdus for insects and especially for mosquito control proposing future ways for their biotechnological applicability. Approximately 24 species of Xenorhabdus and five species of Photorhabdus have been described to have insecticidal properties. These studies have shown genes that are capable of encoding low molecular weight proteins, secondary toxin complexes and metabolites with insecticide activities, as well as antibiotic, fungicidal and antiparasitic molecules. In addition, several species of Xenorhabdus and Photorhabdus showed insecticidal properties against mosquitoes. Therefore, these biological agents can be used in new control methods, and must be, urgently considered in short term, in studies and applications, especially in mosquito control

Functional Genes of Microorganisms, Comprehending the Dynamics of Agricultural Ecosystems

ABSTRACT The microbial composition of different types,in ecosystems (including agro-ecosystems), has been investigated in a rapidly growing number of studies in the past few years. The importance of microorganisms, regarding the maintenance and stability of nutrients in agroecosystems, is a key to maintain the sustainability of a crop. Molecular tools to study microbial communities are possible through many methods such as RISA, DGGE, TGGE, clone libraries, T-RFLP, RAPD, SSCP and more recently NGS (Next-Generation Sequencing). DGGE is widely employed to characterize the diversity and the community dynamics of microorganisms in the environment, making possible to find out specific groups through functional genes, allowing access to data that cannot be obtained by cultural methods. The aim of this paper is to review the functional groups related to agroecosystems and to indicate the critical choice of DNA primers pairs and targeted DNA regions that may be used in PCR-based methods such as the DGGE technique in order to evaluate the microbial communities in a variety of environments

Microbial Diversity: Relevance and Relationship Between Environmental Conservation And Human Health

This work presents bibliographic data on the role and function of microbial diversity. The increasing use of probiotics and prebiotics foods has led to the studies on their actual functions in the human body. It is known that in the environment, microorganisms are extremely important in recycling of nutrients, balance of trophic chains, vital physiological activities in the plants and animals, as well as the conservation of natural habitats. In human food, these microscopic organisms contribute from flavoring products to the synthesis of antimicrobial substances and vitamins essential to living beings